Device for pulling pipes or well casings



July 29 1941- R. E. CHAPMAN 2,251,113

DEVICE FOR PULLING PIPS `OR WEL-L CASINGS Filed Deo. 29, 1959 @www MMX@YQ@ @un j V H ai d ff/pizz. l??? 25d-effi' a 27m/*z @M mi Patented JulyZ9, 1941 A 'llllv'liCE FOR PULLING C'ASING giras entrai-r'.

`Robert 4ll. Chapman, Oakdale, Mass., assignorto, R. E. Chapman Company,Oakdale, YMass., -a 'corporation of Massachusetts f A ApplicationDecember 29, 1939,'Seria'l No. 311,504Y

(ci. g55- 27) 4 Claims.

The present invention relates to an improved device for pulling pipes orwell c'asings, such as are driven Vinto the ground in connection withthe drilling of wells. When drilling an artesian well, it is customaryto drive an outside pipe or casing into the ground as far as ledge rock,before placing the inner casing, and the later removal and salvage ofthis outside casing often presents great difculties.

The object of the present invention is to provide a pulling device,which will enable a pipe or casing to be readily withdrawn from theground by utilizing a pulling force developed from the upstroke of theusual string of drilling tools. The device of the present invention isreadily applied to a drilling rig, without removing any parts therefrom,and in operation, the impact of the drilling tools is applied to thecasing being pulled, Without developing any shocks which will eitherinjure the tools, or damage the casing. The above and other advantageousfeatures of the invention will hereinafter more fully appear from thefollowing description, with reference to the accompanying drawing, inwhich:

Fig. 1 shows a section of outside casing driven into the ground, withthe upper portion of a string of well-drilling tools disposed within thecasing. n

Fig. 2 illustrates the manner of assembling the parts of the pullingdevice on the casing and tools.

Fig. 3 illustrates the operation of the pulling device on the up strokeof the drilling tools.

Figs. 4 and 5 are detail views, in plan, of separate parts of thepulling device.

Referring to the drawing, a pipe or casing I is shown as having beendriven into the ground as the drilling -of the well progresses. In thedrilling of artesian wells, in accordance with the usual practice, thisoutside casing I, ranging from 8 to 14 inches in diameter, is driven inthe required number of lengths, until ledge rock is reached, and whenthe drilling has been carried to the desired depth and the inner casingplaced, it is customary to withdraw this outer casing for further use.Each length of casing I is threaded at its ends as indicated at 2, sothat several lengths of casing can be joined together, as required, bycouplings 3. Consequently, the upper end of the last length of casingthat has been driven presents a coupling 3 extending above the groundlevel, where it is readily accessible for application of the pullingdevice of the present invention.

For the purpose vof withdrawing the Vcasing I, -a heavy cylindricalbushing 4 is provided having ane'xtern'al thread 5,-which` can bescrewed into the open end of the top coupling 3. In order to expediteattachment :of the bushing 4, it is provided with opposed lugs 6 forreceiving a suitable tool, whereby the bushing may be turned. Thebushing 4 provides a central opening 1 of large enough diameter tofreely permit passage of a string of well-drilling tools 8, includingthe heavy drill stem 8a, which are carried by a cable 9 connected to theusual cable socket IB.

When it is desired to pull the casing I, the tools 8, without the drillbit, are rst lowered through the bushing 4 and suspended in the positionshown in Fig. 2. The bushing 4 is then held a sufficient distance abovethe coupling 3, to admit a second Ibushing or hammer II, having anoutside diameter slightly less than the inside diameter of the casing I.The hammer II is in the form of a heavy ring providing a central openingI2 adapted to receive the neck lila of the socket IU. The hammer II alsoprovides a radial slot I3, as shown in Fig. 4, to permit the passage ofthe cable 9 when positioning the hammer, which is then lowered until itengages a shoulder I4 formed on the socket I0, as indicated in dottedlines in Fig. 2. The bushing 4 is then screwed into the coupling 3, asshown in Fig. 3, and it is to be noted that a considerable portion ofthe inside of the bushing 4 overlies the outside portion of the hammerII.

When the drilling tools 8 are lowered and then raised by the usualdrilling motion, the hammer II, being carried by the shoulder I4, willengage the bushing 4 on each up stroke, to impart a blow which istransmitted directly to the casing I through the coupling 3. The forceof this blow is considerable, due to the weight of the tools 8, and isevenly distributed around the entire periphery of the casing I, so thatan extremely effective force is applied upward, to pull the casing outof the ground. Since the outside of the hammer II makes a close fit with4the casing I, it acts as a guide for the tools 8 on their up stroke,and so insures that the socket I0 will be centered in the opening I ofthe bushing 4 as a blow is delivered to the bushing 4, therebypreventing any damage to the tools and casing.

I claim:

1. A device for pulling pipe or well casing, comprising in combination,a casing within the ground, a string of drilling tools movable axiallywithin said casing by a cable, a member secured to the upper end of thecasing, having an opening through which the tools can pass, and a secondmember capable of being freely mounted on the upper end of the string oftools, without withdrawal of said tools from said casing and having anoutside diameter greater than the opening in said first-named member,whereby said members come into contact on the upstroke of the tools toimpart; a pull to said casing.

2. A device for pulling pipe or well casing, comprising in combination,a casing within the ground, drilling tools movable axially within saidcasing by a cable and its socket, a bushing secured to the end of thecasing having an opening to permit passage of said socket and tools, asecond bushing capable of being freely mounted on said socket, withoutwithdrawal of said tools from said casing and having an outside diametersubstantially equal to that of said casing, whereby opposed surfaces ofsaid bushings are brought into contact on the upstroke of the tools toexert a pulling force on said casing.

3. A device for pulling pipe or well casing, comprising a casing withinthe ground, a string oi drilling tools 'connected .to a cable by asocket, a bushing threaded into a coupling carried by the upper end ofsaid casing and having an opening to permit passage of said tools andsocket, and a second bushing having a slot for receiving the cable topermit positioning of said second bushing on said socket, with upwardmovement of the tools by the cable serving to bring said bushings intocontact to developy an upward pull on said casing.

4. A device for pulling pipe or well casing, comprising a casing withinthe ground, a string of drilling tools connected to a cable by a socket,a bushing threaded into a coupling carried by the upper end of saidcasing and having an opening to permit passage of said tools and socket,and a second bushing having a slot'I for receiving the cable, to permitlowering of said second bushing on to a shoulder provided by saidsocket, with upward movement of the socket by the cable serving to bringsaid bushings into contact to transmit a blow to said casing.

ROBERT E. CHAPMAN.

